A tsunami is a series of powerful waves caused by large-scale displacement of water, most commonly in oceans or large lakes. Unlike wind-driven waves or tides, tsunamis originate from significant events such as earthquakes, volcanic eruptions, or underwater explosions. These events rapidly displace a substantial volume of water, creating waves that can travel vast distances with immense force. Their impact can be devastating upon reaching coastal areas.
In 1908, the Messina earthquake and tsunami claimed more than 123,000 lives in Sicily and Calabria, making it among the deadliest natural disasters in modern Europe.
In 1917, the accidental Halifax Explosion triggered an 18-metre high tsunami in the harbour at Halifax, Nova Scotia, Canada.
In 1929, the Grand Banks tsunami came from an earthquake which destabilised sediments, causing them to flow into the ocean and generate a tsunami.
In 1933, the Sanriku event occurred, with movement on normal (extensional) faults which can also cause displacement of the seabed, but only the largest of such events (typically related to flexure in the outer trench swell) cause enough displacement to give rise to a significant tsunami.
As early as World War II (1939-1945), consideration of the use of conventional explosives to induce tsunamis as a tectonic weapon was explored.
As early as World War II (1939-1945), consideration of the use of conventional explosives to induce tsunamis as a tectonic weapon was explored.
On April 1, 1946, the 8.6 Mw Aleutian Islands earthquake generated a tsunami which inundated Hilo on the island of Hawaii with a 14-metre high surge, killing between 165 and 173 people.
In July 1946, during Operation Crossroads, two 20-kilotonne-of-TNT bombs were detonated at Bikini Atoll to test the feasibility of using nuclear weapons to cause tsunamis; the resulting waves were no higher than 3 to 4 m (9.8 to 13.1 ft).
In 1958, a giant landslide in Lituya Bay, Alaska, caused the highest wave ever recorded, with a height of 524 metres (1,719 ft). Two people died.
In 1960, the Valdivia earthquake (Mw 9.5) generated a teletsunami that crossed entire oceans.
In 1962, the Sieberg-Ambraseys scale was used routinely to measure the intensity of tsunamis in the Mediterranean Sea.
In 1963, a massive landslide from Monte Toc entered the reservoir behind the Vajont Dam in Italy, creating a wave that surged over the dam and destroyed several towns, killing around 2,000 people.
In 1963, the Imamura-Iida intensity scale was used routinely to measure the intensity of tsunamis in the Pacific Ocean.
In 1964, the Alaska earthquake (Mw 9.2) generated a teletsunami that crossed entire oceans.
In 1969, an episode of the TV crime show Hawaii Five-O entitled "Forty Feet High and It Kills!" used the terms "tsunami" and "tidal wave" interchangeably.
In 1972, Soloviev modified the Imamura-Iida intensity scale to measure tsunami intensity.
In 1977, the Sumba event occurred, with movement on normal (extensional) faults which can also cause displacement of the seabed, but only the largest of such events (typically related to flexure in the outer trench swell) cause enough displacement to give rise to a significant tsunami.
On March 31, 1979, a destructive meteotsunami occurred at Nagasaki.
On July 12, 1993, the Okushiri, Hokkaidō tsunami created waves 30 metres (100 ft) tall, destroying all the wood-framed structures in the area.
In 1998, the Papua New Guinea tsunami came from an earthquake which destabilised sediments, causing them to flow into the ocean and generate a tsunami.
In 2001, Tappin published a study on tsunamis originating at locations away from convergent boundaries, including Storegga, Grand Banks, and Papua New Guinea.
During the 2004 Indian Ocean earthquake, it was noted by media sources in Sri Lanka that some animal species may have sensed the tsunami, but the evidence is controversial.
In 2004, ten-year-old Tilly Smith warned her family and others on Maikhao beach in Phuket, Thailand, about an imminent tsunami after learning about them in school, saving dozens of lives.
In 2004, the Indian Ocean earthquake (Mw 9.2) generated a teletsunami that crossed entire oceans.
In 2013, following the intensively studied tsunamis in 2004 and 2011, a new 12-point scale was proposed, the Integrated Tsunami Intensity Scale (ITIS-2012), intended to match as closely as possible to the modified ESI2007 and EMS earthquake intensity scales.
In the 2004 Indian Ocean tsunami, drawback was not reported on the African coast or any other east-facing coasts that it reached. This was because the initial wave moved downwards on the eastern side of the megathrust and upwards on the western side. The western pulse hit coastal Africa and other western areas.
On June 15, 2006, a destructive meteotsunami occurred at Menorca, causing damage in the tens of millions of euros.
In 2011, the Tōhoku earthquake (Mw 9.0) generated a teletsunami that crossed entire oceans.
In 2013, following the intensively studied tsunamis in 2004 and 2011, a new 12-point scale was proposed, the Integrated Tsunami Intensity Scale (ITIS-2012), intended to match as closely as possible to the modified ESI2007 and EMS earthquake intensity scales.
The Fukushima Daiichi nuclear disaster was triggered by the 2011 Tōhoku earthquake and tsunami, when waves exceeded the height of the plant's sea wall and flooded the emergency generators. In 2011, the tsunami toppled more than 50% of tsunami barriers walls and caused catastrophic damage.
In 2013, following the intensively studied tsunamis in 2004 and 2011, a new 12-point scale was proposed, the Integrated Tsunami Intensity Scale (ITIS-2012), intended to match as closely as possible to the modified ESI2007 and EMS earthquake intensity scales.
In 2013, following the intensively studied tsunamis in 2004 and 2011, a new 12-point scale was proposed, the Integrated Tsunami Intensity Scale (ITIS-2012), intended to match as closely as possible to the modified ESI2007 and EMS earthquake intensity scales.
In 2018, the eruption and collapse of Anak Krakatoa killed 426 and injured thousands due to a lack of warning.
The 2022 Hunga Tonga–Hunga Ha'apai eruption triggered a tsunami. Tsunamis have been triggered by a number of volcanic eruptions.